The Health Benefits of Oats (Avena Sativa)

For Lowering Cholesterol, Preventing Heart Disease, and More

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Oats (Avena sativa L.) are grown worldwide to provide a vital food staple for people in many countries. Avena sativa is commonly eaten (or taken as a medicinal supplement) for its highly-acclaimed health benefits. Other common names for Avena sativa include, avena (Spanish), hafer (German), ma-karasu-mugi (Japanese), and oats.

The Avena sativa plant is comprised of a seed (oat), leaves and stems (oat straw) and bran (the outer layer of the whole oats). Surprisingly, various parts of the Avena sativa plant are used to make medicinal herbal supplements, providing a wide range of health benefits.

To fully understand the medicinal properties of Avena sativa, it’s important to learn about the various parts of the plant, including:

  • The fresh milky seed: These are oats that are harvested early, during the “milky” stage. Early-harvested oats have the highest level of minerals such as potassium and magnesium (available as a supplement).
  • The mature seed: These are eaten as food (oatmeal) which is rich in nutrients such as silicon, manganese, zinc, calcium, phosphorus, and vitamins A, B1, B2, and E. This is the endosperm, which is the usual product of milling.
  • Whole oat groats: Groats are whole grains—the hulled kernels including the cereal germ and fiber-rich bran, as well as the endosperm. Whole oat groats contain high levels of nutrients such as soluble fiber, proteins, unsaturated fatty acids, vitamins, minerals, and other phytochemicals.
  • Oat straw: These are tge leaves and stems of the plant, which contain very high iron levels, as well as manganese and zinc.
  • Oat beta-glucan (oat bran): This soluble fiber has been linked to improving heart health and lowering cholesterol. Oat bran can be found as a whole-grain food product as well as a medicinal supplement.

The outer husk of the oat must be removed as it is not digestible by humans.

Health Benefits

Oats are a rich source of protein, minerals, fats, beta-glucan, polysaccharides, and dietary fiber. They also contain many other nutrients such as antioxidants and lipid (fat) lowering chemicals such as flavonoids, saponins, sterols and more.

Avena sativa (oats) has been examined in clinical research studies as a remedy for many medical conditions, but more clinical research evidence is needed to prove its safety and efficacy for conditions such as:

  • Anxiety
  • Bladder weakness
  • Constipation
  • Diverticulosis
  • Gout
  • Inflammatory bowel disease
  • Irritable bowel syndrome (IBS)
  • Joint and tendon disorders
  • Kidney conditions
  • Nerve disorders
  • Opium and nicotine withdrawal
  • Gallstones
  • Skin disorders
  • Stress

Oats have been extensively examined in clinical research studies and have been found to offer many health-promoting effects, including the following.

Antioxidant Effects

A 2015 research paper reported that oats (Avena sativa L.) contain several antioxidants including:

  • Vitamin E
  • Flavonoids
  • Phenolic acids

Cholesterol-Lowering Effects

Studies revealed hypolipidemic (lowering of fats in the blood) effects oat beta glucan. Eating oatmeal, and oat bran lowered the total blood cholesterol and LDL (bad) cholesterol levels.

Oat bran was found to be a fiber source that significantly lowered the total and low-density lipoprotein (proteins that combine with and transport fats in the blood), lowering risk of heart disease in those with mildly high cholesterol levels.

Avena sativa is thought to lower cholesterol by providing high amounts of fiber in the diet. At least 750 milligrams (mg) of soluble fiber per serving supports a health claim to lower the risk of heart disease.

Oat bran may block substances that contribute to diabetes and high cholesterol; it may also provide a feeling of fullness, helping to promote weight loss.

Heart Health

In 1997 the Food and Drug Administration (FDA) approved the heart health benefit of fiber from oats, allowing products to list it on their packaging. Oat bran was also found in some studies to lower blood pressure.

Obesity (Weight Reduction)

In a clinical trial of obesity and oats, study participants with a body mass index (BMI) of over 27 were divided into two groups. One group was treated with beta glucan oat cereal, the other took a placebo.

After 12 weeks, the group that took oats reduced body weight, body fat, body mass index (BMI), and waist-to-hip ratio measurement. There were no adverse effects in any of the study subjects.

Antidiabetic Effects

Studies have been done to explore whether long-term intake of oats or oat bran improves insulin sensitivity, but a 2014 review of studies found no evidence that oats are effective in that capacity.

However, another review of studies found oat bran beta glucan had a beneficial effect on metabolic syndrome and glycemia. This shows that research is still determining whether there are health benefits in blood sugar control.

Antimicrobial Effects

Extracts from Avena sativa were found to offer antibacterial properties against Staphylococcus aureus, and E. coli, as well as other bacteria.

Skin Benefits

Studies found that preparations from oatmeal (such as an oatmeal bath, emollients, and oat colloidal extracts) were effective in the treatment of several inflammatory skin conditions including:

  • Dermatitis (inflammation of the skin)
  • Pruritis (a condition of the skin involving itching)
  • Acne
  • Eczema (treated with dried seed decoction)

Nervous System Effects

Studies found that Avena sativa supported cognitive performance in stressful situations and boosted overall healthy mental functioning.

In one study, a 1,600 mg dose of oat herb extract was found to improve attention, concentration, and the ability to maintain focus during tasks performed by adults at various levels of cognitive functioning.


Older studies of Avena sativa reported that extracts lowered the craving for nicotine, reducing the number of cigarettes smoked each day. 

Gastrointestinal (GI) System

Oat bran has been studied as a possible treatment for GI disorders, such as ulcerative colitis. One older study showed to improve a process that lends itself to an increase in gut flora (called endogenous butyrate production) and provide relief of abdominal pain.

Immune Response

Studies have found that beta glucan (oat bran) helped white blood cells reach the site of infection quickly and improved the white blood cell’s bacteria-killing properties.

Possible Side Effects

Oat products are considered likely safe for most people, including:

  • People who are pregnant
  • People who are breastfeeding
  • Children


A contraindication is a specific situation in which a treatment, drug or medicinal supplement, should not be given because it may harm a person. Contraindications for taking oat products include:

  • People diagnosed with celiac disease or other disorders of the digestive tract
  • Those with intestinal obstructions
  • Those with digestive disorders that slow down the digestive process (this could lead to an intestinal blockage).
  • Children with a condition called atopic dermatitis, as they may have an increased risk of oat allergies

Side Effects

Side effects of oats may include:

  • Flatulence (gas)
  • Bloating
  • Anal irritation
  • Skin irritation (when oat containing products are used topically (on the skin).

To minimize side effects, start with a lower dose, then gradually increase to the desired amount and the body will slowly adjust. Side effects are likely to subside.

Special Precautions

Those who have trouble chewing or swallowing (such as after a stroke or if you have ill-fitting dentures or loose teeth) should avoid eating oats. When oats are not chewed properly, a blockage in the intestines could occur.

Oats, oat milk, oat bran

Verywell / Anastasia Tretiak

Selection, Preparation, and Storage

Oat bran products should be taken along with plenty of water, to ensure good distribution of the fiber in the bowel.

The Dietary Reference Intake for total fiber for adults age 50 or younger is 38 grams for men and 25 grams for women, and for those over age 50 it is 30 grams per day for men and 21 grams for women. A 1/2 cup of Quaker oatmeal contains 2 grams of soluble fiber.

Milky oats are harvested during a stage that only lasts around a week. This occurs right before the oat begins to flower and before the seed hardens into the oat grain that is commonly eaten at the breakfast table. A tincture of milky oats is made to preserve the potency of the plant. A dried form is also made and used as a nutritive tonic.


When purchasing supplemental forms of the Avena sativa plant, it’s important to look for a product that is organic, all-natural, and certified to ensure purity and potency by a third-party organization, such as the U.S. Pharmacopeia, NSF International, or

Ensuring that an oat product, such as milky oats, has been harvested at the right time in the plant’s growth stage is vital to getting a product that has therapeutic, health-boosting properties.

Types of Oats as Food Sources

There are several types of oats available as food sources, it’s important to note that the nutritional content is relatively the same whether the oats are cut, rolled or ground. The primary difference between the various types of oats available is their fiber content, as well as the amount of time it takes to prepare them.

Whole-Grain Oats

Whole grain oats are also known as whole oat groats or whole oat kernels. This type of oat food product is minimally processed. The outer (inedible) hull is removed but they still have a chewy texture and are said to taste best when eaten hot. Whole grain oats may take up to an hour to cook.

Steel-Cut Oats

Steel-cut oats are whole oat groats, but they have been cut into smaller pieces to decrease the cooking time. Instead of taking an hour to cook, steel-cut oats take only about 20 minutes.

Scottish Oats

Oats that are ground into broken pieces, they take only about 10 minutes to cook on high heat. Scottish oats originated in Scotland, they have a creamy texture and are perhaps the best choice for making refrigerator oats (see recipe in the Common Questions section).

Rolled Oats

Rolled oats, such as the Quaker brand, are steamed and softened, then they are rolled into flakes. The processing lengthens the shelf life of the product without majorly impacting the nutritional value. They are quick to cook, taking approximately 10 minutes.

Instant Oats

Instant oats are steamed and rolled, but for a longer time than rolled oats, thus, they are partly cooked when purchased. They have a creamy, non-chewy texture, and can be prepared quickly by adding hot water. The health benefit is close to that of rolled oats, but be sure to avoid the sugar-laden pre-sweetened/flavored variety of instant oats.

Oat Bran

Oat bran is very high in soluble fiber. It’s not considered whole grain because it is comprised of just the bran layer, but it offers the health benefits of whole grain. Oat bran can be cooked in just a few minutes on the stovetop or it can be added to other cereals, yogurt, or smoothies to increase the daily fiber content in the diet.


Several studies involved the use of Avena sativa, which was ingested as a tea made with 3 grams of the plant, boiled in 250 milliliters (ml) of water. After straining and cooling the tea, it was taken several times each day and shortly before going to bed at night.

Frequently Asked Questions

  • Can oats be eaten raw?

    Yes, Soaking raw oats overnight in any type of milk (for example, cow's milk or a nut milk such as almond, cashew, or coconut) in the refrigerator will soften them enough to be eaten. One cup of milk to one cup of oats is a good ratio. Overnight oats can be flavored and enhanced with fresh or dried fruit, raw or roasted nuts or seeds, nut butter, fresh coconut, granola, spices, orange zest, or vanilla extract.

  • What nutrients are in oat milk?

    One cup (8 ounces) of unsweetened oat milk contains:

    • 120 calories
    • 3 grams (g) protein
    • 16 g carbohydrates
    • 5 g fat
    • 1.9 g fiber

    Most brands are fortified with calcium, vitamins A and D, and riboflavin. Oat milk tends to have a bit more fiber than other plant-based milks.

  • When can babies begin eating oats?

    Babies usually can start eating oatmeal as soon as the pediatrician gives the OK to start solid foods—typically around 6 months but no earlier than 4 months.

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15 Sources
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